Natural glues and fouling management by interfering with glue curing

Abstract

Multidisciplinary approaches and modern technology provide insights to glue curing that are stimulatingand controversial. Our team applies classic and modern theory and techniques to the study of barnacle glue. Techniques include physical measures, bacteriology, behavior, physiology, biochemistry, microscopy, spectroscopy, tomography, tandem mass spectrometry, molecular biology and proteomics. Theory is grounded in evolution and previous literature. Here, we use data from these techniques to support the hypothesis that barnacle glue curing is similar toblood clotting and propose a model for how glue cures. Similar to blood clotting, barnacle glue curing involves enzymatic activation of precursors and rearrangement of structural molecules to form a crosslinked material. Barnacle larval settlement, bacteriology and biochemical data show glue contains large amounts of small peptides. Their role in glue curing has been overlooked. The peptides comprise 15 to 30% of partially cured glue. Because they have little secondary structure, the peptides can associate with binding domains on the substrate and interface with the larger, well-described structural proteins known in barnacle glue. Enzymes participate in curing of barnacle glue. Siloxanes impact glue-curing enzymes. They potentiate trypsin activity and inhibit transglutaminase activity. Changing enzymeactivity impacts how glue cures. Disrupting the curing process of biological glues is central to effective cleaning strategies for fouling management. Thus silicones that interfere with enzyme activity have potential as additives in easy cleansurfaces. The environmental impacts of organosilicones that are generated by biological processes need to be addressed